Epithelioid sarcoma is extremely rare. Among all cancers, soft tissue sarcomas make up only about 1%, and ES accounts for just 1% of all soft tissue sarcomas diagnosed each year in the U.S. Experts estimate that fewer than 1,000 people in the country currently have this disease. Distal-type ES primarily affects teenagers and young adults, while proximal-type ES is more likely to develop in adults.
Epithelioid sarcoma (ES) is a rare type of soft tissue cancer that begins as a lump, most commonly in the hands, forearms, fingers, lower legs, or feet. However, it can develop in other parts of the body as well. Over time, additional lumps may appear, and in some cases, open wounds (ulcerations) form on the skin above the tumor. This type of sarcoma grows slowly, often going unnoticed for months or even years before symptoms become apparent.
There are two forms of epithelioid sarcoma:
- Distal type – The most common form, which affects extremities such as the hands, feet, lower arms, and lower legs.
- Proximal type – A rarer and more aggressive form that develops closer to the body’s core, including areas like the chest, abdomen, armpits, genitals, head, or neck.
Here’s a medical illustration of epithelioid sarcoma, highlighting its tumor formation and cellular abnormalities.
Symptoms and Causes
Epithelioid sarcoma may not cause noticeable symptoms in its early stages. As the tumor grows, common symptoms include:
- A new lump or swelling, which may be small or large.
- Open wounds (ulcerations) on the skin over the lump.
- Pain, especially if the tumor presses on nerves or muscles.
- An existing lump that increases in size.
What Causes Epithelioid Sarcoma?
Scientists have not identified the exact cause of ES, but they link it to mutations in the SMARCB1 gene, which plays a role in protein production. In most cases, these genetic changes occur spontaneously during a person’s lifetime rather than being inherited.
Certain factors may slightly increase the risk of developing ES, including:
- Previous radiation therapy for other cancers.
- Genetic conditions like Li-Fraumeni syndrome, Neurofibromatosis, Retinoblastoma, and Gardner syndrome.
- While ES does not always metastasize, when it does, it typically spreads to the lymph nodes, lungs, or bones.
How Do Doctors Diagnose Epithelioid Sarcoma?
Healthcare providers use several tests to confirm an ES diagnosis, including:
- Physical examination to assess lumps and swelling.
- Biopsy to analyze tissue samples.
- Blood tests to check for cancer markers.
- Imaging scans such as MRI, CT, or PET scans to determine the tumor’s size and location.
What Are the Treatment Options?
Doctors choose treatments based on the tumor’s size, location, and spread, as well as the patient’s overall health.
- Surgery – The primary treatment involves removing the tumor. If cancer has spread, surgeons may also remove affected lymph nodes.
- Radiation therapy – High-energy X-rays help shrink tumors before surgery or destroy any remaining cancer cells afterward.
- Chemotherapy – If ES has metastasized, doctors may recommend chemotherapy drugs, which are usually delivered through an IV but can also be taken orally or applied topically.
- Targeted drug therapy – This treatment targets specific cancer-causing genes or proteins. Tazemetostat is a commonly used drug for cases where surgery cannot fully remove the tumor.
Can Epithelioid Sarcoma Be Cured?
Doctors can cure ES if they remove the entire tumor. However, complete removal is not always possible. If surgery is not an option, patients may undergo a combination of treatments to manage the disease and maintain their quality of life. Because ES grows slowly, many people live fulfilling lives even with the condition.
What Is the Survival Rate?
Survival rates vary widely due to the rarity of ES. Studies report five-year survival rates ranging from 25% to 92%, depending on the case. Early detection and treatment improve the chances of long-term survival.
Anyone who notices an unusual lump should seek medical attention. Although ES frequently appears on the hands, forearms, fingers, lower legs, or feet, it can develop anywhere in the body.
More information: Diagnosing Soft Tissue Sarcoma
